Muslims usually don't drink alcohol. I say usually because I know quite a lot of Muslims that do drink some alcohol and do other stuff they shouldn't do. But never question their religion!!! Might get you into trouble.
Now the prohibition can be explained quite easily using the following verse in the Quran:
“O ye who believe! Intoxicants and Gambling, (Dedication of) stones, And (divination by) arrows, Are an Abomination – Of Satan’s handiwork; Eschew such (abomination), That ye may prosper.” [Al-Qur’an 5:90]
Intoxicants is a bit vague, but we have a nice little hadeeth that tells us specifically:
“Alcohol is the mother of all evils and it is the most shameful of evils.” from Ibn-I-Majah Volume 3, Book of Intoxicants, Chapter 30 Hadith No. 3371.
OK, we have set the stage for a wonderful session of apologetics. As some people might know (or don't) you will find alcohol in quite a lot of nutritious products. Bread, apple juice, kefir, grape juice all contain "some" alcohol (around 0.1% to 0.5%). Even your own body produces alcohol.
One would think that you can't possibly be a Muslim and eat and drink at the same time. Would make all Muslims dead corpses, wouldn't it? (read on)